Folded box gluing machine for producing folded boxes from blanks

ABSTRACT

Known folded box gluing machines for producing folded boxes ( 1 ) from blanks comprise—a folding station ( 3 ), in which the parts of blanks provided with an adhesive strip are folded,—an adjoining transfer station ( 5 ) which is configured as a transport device and has at least two conveyer belt pairs, each consisting of an upper and a lower belt ( 7, 8 ) and a device for ejecting defective boxes ( 11 ) and—a collection and pressing device ( 6 ), in which the flat folded boxes are pressed together, in order for the adhesive to bind. In order to eject wide boxes ( 11 ) from the machine, which have been identified as defective, the ejection device comprises the following elements:—at least one blade ( 12 ) which cuts in the direction of transport and which is mounted at the beginning of the transfer station ( 5 ) between the two conveyer belt pairs ( 7, 8 ), in such way that it can be lowered into and withdrawn from the direction of transport of the boxes ( 11 ), and a device adjacent to each longitudinal side of the transfer station ( 5 ) for laterally removing the box side sections ( 11.1, 11.3 ) from the machine, which have been separated during the longitudinal cut.

FIELD OF THE INVENTION

The invention relates to a folding box gluing machine for producingfolded boxes from blanks with a folding station and a downstreamtransfer station that has at least two conveyor belt pairs eachconsisting of an upper belt and a lower belt and an ejection device fordefective boxes, and a collection and pressing device in which thefolded boxes are pressed together while the adhesive cures.

BACKGROUND OF THE INVENTION

The ejection device serves for the elimination of all identifieddefective boxes from the collection and pressing device, before a streamof overlapping boxes is produced at the beginning of the collection andpressing station. In the transfer station the boxes are stilltransported individually and are spaced apart, so that an individual boxcan be easily pulled out without disturbing the preceding and succeedingboxes. Defective boxes are boxes which are not sufficiently covered withadhesive, boxes with folding defects or boxes which during an identitycheck have not been identified as not being the type of box now beingfilled.

Such a generic folding box gluing machine is described in the brochure“Diana 115-3 Diana 125-3, die universellen Faltschachtel-Klebemaschinen”of the applicant. The described machine has an add-on ejector that isbuilt into the transfer station and that ejects boxes identified asdefective. The ejector for the elimination of defective boxes is mountedon a longitudinal side of the machine. It consists of a clamping rollmounted on a rotary disk which seizes the part of a defective boxprotruding beyond the belt pair, pulling it from the machine.

The known ejection device, by means of which a box between the conveyorbelt pairs is pulled out to one side, cannot be used with large boxesmore than 500 mm wide. They are not capable of pulling such large boxesfrom the machine at the required speed without damaging the precedingand succeeding boxes.

OBJECT OF THE INVENTION

It is therefore the object of the invention to improve a generic foldingbox gluing machine so that identified defective boxes of large width canbe ejected from the machine.

SUMMARY OF THE INVENTION

This object is achieved in that the ejection device comprises at leastone blade cutting in a conveying direction and supported at an upstreamend between the two belt pairs so that it can be lowered into theconveying plane of the boxes and lifted therefrom, and downstream oneach longitudinal side of the transfer station a device for lateralextraction from the machine of the side parts separated by the blade.

The ejecting device built according to the invention has the furtheradvantage of being able to eject boxes with bilaterally inwardly foldeduncovered longitudinal flaps. When such boxes are pulled out as a wholeonly to one side, there is a danger that one of the conveyor belts canbe torn off its guide by the box. The reason for this is that as adefective box is being pulled out through one of the conveyors theinwardly folded uncovered longitudinal flap projecting past the otherconveyor catches on the conveyor belts of the other conveyor, pullingits upper belt off its guides.

In a particularly advantageous embodiment with two longitudinal blades,each arranged inside next to the conveyor belt pairs, the box isseparated into three parts. This results in two small lateral partswhich can easily be pulled off to the respective sides and a middle partwhich is deflected downward by the conveyor belts. The separation intothree parts has the advantage of ejecting extremely wide boxes, as wellas boxes with many separate parts, for instance folded-bottom boxes. Thetwo longitudinal cuts can be placed so that all box parts affecting thebelts when they are pulled off remain on the middle part so they can bedeflected downward.

The construction of the longitudinal blade as a circular blade makes itpossible to cut thick boxes made of cardboard or multilayered corrugatedboard with high weight per surface unit. Therein:

BRIEF DESCRIPTION OF THE DRAWING

The invention is further described with the aid of the drawingrepresenting an embodiment shown in a simplified form. Therein:

FIG. 1 shows a schematic side view of the individual stations of afolding box gluing machine, and

FIG. 2 shows a part of the transfer station with the ejection device ina perspective view.

SPECIFIC DESCRIPTION

In the conveying direction (in the figures from right to left) thefolding box machine starts with a feeder 1 which picks up blanks 11(FIG. 2) from a stack, one after the other at high speed, and feeds themindividually to the downstream processing stations. The feeder 1 isfollowed by a preliminary creaser 2, which in the present embodiment isdesigned in two stages. The preliminary creaser 2 comprises foldingelements serving to fold the blanks' flaps back and forth, so that thecorresponding longitudinal lines are made pliable through bendingthrough 180°. The two-stage embodiment makes it possible to break inmore longitudinal and transverse lines and to perform additional foldingoperations.

In the case of certain box shapes two adhesive applicators are providedin the preliminary creaser 2 and serve to apply additional adhesivelongitudinal strips. The next processing station downstream of thepreliminary creaser 2 is a folding station 3 at whose upstream end is anapplicator 4 for adhesive, usually glue. The adhesive applicator 4 hasglue nozzles or glue disks by means of which adhesive is applied to theblanks in strips. Prior to folding of the flaps provided with adhesive,a check of the applied adhesives takes place. For this purpose, theadhesive strip is scanned without touching by a so-called glue seamcontrol device serving as a sensor means. If the adhesive strip does notconform to required quality, a central controller is advised that thebox is defective.

At the downstream end of the folding station 3, the folded box ischecked by other sensors for folding defects. For this purposephotoelectric cells are provided which scan the length of the box. Ifthe length of the folded box does not correspond to the predeterminedformat, for instance because one flap was irregularly folded, this boxalso is identified as defective for the central controller of the gluingmachine.

The folding station 3 is immediately followed by the transfer station 5,which is shown in FIG. 2 in larger scale. The primary task of thetransfer station 5 is to feed the blanks 11 with still unbonded adhesiveseams to a downstream collection and pressing station 6, with all partsin the correct position. At the transfer point between the transferstation 5 and the collection and pressing station 6, a stream ofoverlapped folded boxes is formed. The collection and pressing station 6has pressure belts by means of which the glued seams are kept underpressure until the adhesive has fully cured.

As a conveying device for the folded boxes the transfer station 5comprises two pairs of conveyor belts, each consisting of a lower belt 7and an upper belt 8. The folded blanks are transported between the upperreach of the lower belt 7 and the lower reach of the upper belt 8 at adistance from each other, the upper belts 8 holding down the folded sideflaps of the blanks. The conveyor belts 7 and 8 have to be transverselyadjustable in order to accommodate various blank widths. For thispurpose each of the lower conveyor belts 7 is supported on a rollingcarriage 9 extending in the transport direction and transverselyadjustably suspended in the machine frame by means of an adjustmentspindle. Correspondingly each upper conveyor belt 8 is supported on aso-called roller rail 10 that can be transversely displacedsynchronously with the respective rolling carriage 9 in order toestablish the desired work position of the belts 8. The belts 7 and 8are driven by a central drive of the folding box gluing machine.

The transfer station 5 comprises an ejection device that ejects allidentified defective boxes 11 from the folding box gluing machine. Theconstruction and operation of the ejection device are described in FIG.2.

The ejection device comprises at least one blade 12 cutting in theconveying direction and is arranged at the upstream end of the transferstation defined between the two pairs of conveyor belts 7 and 8. Theblade 12 is supported in the frame of the transfer station 5 so that itcan be raised and lowered. It is lowered into a use position for thecutting operation in the transport plane of the boxes 11 and lifted outof the transport plane into an inactive position.

Preferably two identically built blades 12 are each arranged inside andclose to each of the pairs of a conveyor belts 7 and 8. They sever adefective box 11 into three parts 11.1, 11.2, 11.3.

Preferably the blades 12 are circular blades supported freely rotatablyin respective protective housings 13 that for cutting are moved downwardagainst a mating roller 14. Each mating roller 14 reaches peripherallyfrom underneath up to the height of the upper conveying side of thelower conveyor belt 7, this way supporting a box 11 from below duringcutting. Therefore the protective housings 13 of the circular blades 12are each fastened to the respective roller rail 10. Each of them can beswung outward into a parked position when they are not needed. Theprotective housings 13 are each mounted on a lever 15, which can swingoutward about the respective roller rail 10 and at the same time istransversely displaceable in order to be able to change its positionwith respect to the respective belts 7 and 8.

In addition the protective housings 13 are supported height-adjustablein order to be able to adjust the blades 12 to various box 5thicknesses. This way in case of a format change, each housing 13 withthe respective blade 12 is automatically positioned with the roller rail10. The left protective housing 13 is shown partially open in FIG. 2 inorder to show the mounting of the blade 12 inside the housing 13. Theblade 12 is a attached to holder 15 that is vertically movable withinthe required lifting range by means of a pneumatic piston-cylinder unitin order to move the cutting edge of the blade 12 against the matingroller 14.

Downstream of the blades 13 in the transport direction on eachlongitudinal side of the transfer station 5 a device is provided for thelateral removal from the machine of the side parts 11.1 and 11.3separated by the longitudinal cut. Each such device has a belt conveyor17 which extends from the outside through a recess in the upper rollerrail 10 into the vicinity of the conveyor belts 7 and 8. The transportdirection of the belt conveyors 17 runs approximately at an angle of 45°with respect to the transport direction of the belt pairs 7 and 8 andextends outward above a smooth table 18 fastened outside to the rollingcarriage 9. The upper surface of the table 17 forms a counter-surfacefor the lower reach of the belt conveyor 17 suspended on the roller rail10 and supports a box part 1.11 or 11.3 that is discharged. An upstreamguide roller 19 of the belt conveyor 17 can be lifted and lowered bymeans of a pneumatic piston-cylinder unit 20. When the guide roller 19is lowered onto a box part 11.1 or 11.3 projecting beyond the conveyorbelts 7 and 8, the belt conveyor 17 pulls the box part 11.1 or 11.3 overthe table 18 outward and removes it from the machine. By raising theupstream guide roller 19, the belt conveyor 17 is inactivated. In orderto be able to adjust the height of each belt conveyor 17 to the variousbox thicknesses, it is suspended height-adjustably from a support arm 21fastened to the upper roller rail 10. In addition it is pivotal on thesupport arm 21 about a vertical axis for adjustment of its angle withrespect to the transport direction.

FIG. 2 shows the preferred embodiment with two blades 12 each arrangedinside next to a respective pair of conveyor belts 7 and 8. When a box11 is identified by one of the sensor means as defective, the centralcontroller of the folding box gluing machine determines when this box 11will enter the transfer station 5. After the preceding good box passesthe blades 12, they are lowered and cut the defective box blank 11 intothree parts 11.1, 11.2, and 11.3 during passage. In case a good boxblank follows, the blades 12 are raised back into the inactive positionimmediately after the passage of the defective box blank 11. The twobelt conveyors 17 are subsequently positioned after a delay on the boxparts 11.1 and 11.3 projecting outward between the pairs of conveyorbelts 7 and 8 while the belt drive is turned on. In this manner the beltconveyors 17 pull the box parts 11.1 and 11.3 outward over the tables18, thereby removing them from the machine. Preferably the beltconveyors 17 are positioned so that their angle to the transportdirection is 45°, and their speed is set at 2½ times the conveying speedof the belts 7 and 8. This way during their removal the box parts 11.1and 11.3 continue to be moved downstream in the transport direction ofthe conveyor belts 7 and 8 and at their conveying speed. This preventspreceding or succeeding boxes from being damaged during their run. Themiddle part 11.2 of the box 11 resulting from the longitudinal cuts isremoved downward. It can be removed from the machine by means of atransverse conveyor provided at the bottom, or it can be comminuted by ashredder arranged at the bottom into shreds that are fed to a collectionreceptacle.

Instead of the two blades 12 it is possible also to provide only asingle blade 12 between the pairs of conveyor belts 7 and 8, if this isacceptable for the box format to be processed, for instance when the box11 is so small that the two parts produced by the cut can be pulled outeach on one side of the machine. The arrangement with two blades 11 canalso process box formats containing box parts which create problems whenthey are laterally pulled out from between the conveyor belts 7 and 8.The two longitudinal cuts can then be positioned so that all box partswhich would hit against the belts 7 and 8 remain on the middle part 11.2and in this way are evacuated downward. This way also complicated boxshapes, particularly folded-bottom boxes, can be ejected from themachine without problems.

1. A box-gluing machine comprising: transport means including twotransversely spaced and parallel conveyors extending in a transportdirection for gripping and continuously advancing a succession of boxblanks in a transport direction along a path; treatment means along anupstream portion of the path for folding and applying glue in strips tothe blanks as they are advanced by the conveyors; sensor meansdownstream of the treatment means for detecting defective blanks grippedby the conveyors; a vertically displaceable blade between the conveyorsdownstream of the sensor means and displaceable between a use positionengageable with a box blank being advanced by the conveyors and aninactive position unengageable with a box blank being advanced by theconveyors; actuator means connected to the blade and to the sensor meansfor displacing the blade into the use position when a defective blank isdetected and passes the blade and for thereby severing the defective boxblank into at least two side parts each gripped by a respective one ofthe conveyors; and respective extraction means downstream of the bladeand outside the belt conveyors for pulling the side parts transverselyin opposite directions through the respective conveyors out of themachine.
 2. The box-gluing machine defined in claim 1 wherein each ofthe conveyors comprises an upper belt and a lower belt, the side partseach being pinched between one of the upper belts and the respectivelower belt.
 3. The box-gluing machine defined in claim 1, furthercomprising a second vertically displaceable blade transversely spacedfrom the first-mentioned blade and displaceable synchronously with thefirst blade by the actuator means like the first blade between a useposition and an inactive position, each of the blades being transverselyclosely juxtaposed with a respective one of the conveyors, whereby acenter part can be cut from a blank by the first and second blades frombetween the side parts.
 4. The box-gluing machine defined in claim 1wherein the blade is a circular blade lying in a plane parallel to thedirection.
 5. The box-gluing machine defined in claim 1 wherein the useposition is below the inactive position.
 6. The box-gluing machinedefined in claim 1 wherein the extraction means each include a beltextending at an acute angle to the direction away from a respective oneof the conveyors.
 7. The box-gluing machine defined in claim 6 whereineach of the belts extends at an angle of substantially 45° to therespective conveyor.
 8. The box-gluing machine defined in claim 7wherein each of the belts is operated at a speed equal to 21/2 times anadvance speed of the blanks in the direction.
 9. A box-gluing machinecomprising: transport means including first and second transverselyspaced and parallel conveyors extending in a transport direction forgripping and continuously advancing a succession of box blanks in atransport direction along a path; treatment means along an upstreamportion of the path for folding and applying glue in strips to theblanks as they are advanced by the conveyors; sensor means downstream ofthe treatment means for detecting defective blanks gripped by theconveyors; respective first and second vertically displaceable andtransversely spaced blades between the conveyors downstream of thesensor means and displaceable between a use position engageable with abox blank being advanced by the conveyors and an inactive positionunengageable with a box blank being advanced by the conveyors; actuatormeans connected to the blades and to the sensor means for displacing theblades into the use position when a defective blank is detected andpasses the blades and for thereby severing the defective box blank intotwo side parts each gripped by a respective one of the conveyors and acenter part; and respective extraction means downstream of the blade andoutside the belt conveyors for pulling the side parts transversely fromthe respective conveyors out of the machine.